Attaching parts to wooden poles



Jan. 8, 1952 M. w. MANSON ATTACHING PARTS TO WOODEN POLES Filed Sept. 7,1946 Patented Jan. 8, 1952 ATTACHING PARTS T oqn srotns Magnus WilliamManson, Johannesburg I I I t p I TransvaaLUnion ofSouth Africa a v 1 viI Application September 7, 194c,jseria1 mists. 111' Union of SouthAfrica September 1 Claim. (01. 287 54 This invention relates to meanswhereby parts such as cross arms for wire lines, pole stays and otherfittings are attached to wooden poles.

Cross arms for telephone and telegraph lines are sometimes attached bymeans of a bolt passed through a hole bored in the wood and arestabilized by cutting a flat in the surface of the pole which forms aseating for the cross arm or other part rigidly connected to thecrossarm. In either case cutting of'the wood mechanically weakens thepole and exposes the timber to deterioratinginfluences. Moreover if thepole warps by twisting, the cross arm is thrown out of perpendicularitywith the line of wires, necessitating the pole being loosened intheground and rotated to compensate for the twist.

Cross arms are also attached to wooden poles by a halved clamp device,one half of the clamp being provided as a saddle welded to thearm andpresenting a series of seating'edges, which in practice make little morethan point contacts with the pole. The other half of the clamp is astraight barof channel section that presents the channel edges to thepole and accordinglyalso makes virtual point contacts with a pole. As aconsequence of these contact formations the surface fibres of the poleare crushed; destroying the native resilience of the timber which is afactor in maintaining the tight grip of the clamp on the pole.Thereafter periodical weather changes cause alternate diametralexpansions and. contractions of the good timber remaining within thecrushed zone. These increase the radial extent of the initial damage andthe rate of destruction in this manner is accelerated by the repeatedretightenings of the clamp which are thus rendered necessary in order tomaintain the arm rigidly at its initial position on the pole and toprevent its slipping down the pole.

It is an object of the present invention to overcome the drawbacksmentioned and to provide means by which cross arms can be attached towooden poles with minimum destruction of the timber and in a mannerwhich renders the attachment secure over long periods.

A device according to this invention comprises clamp elements which maybe two or more in number and which collectively encircle and makeinternal contact with a considerable circumferential extent of thesubstantially cylindrical surface of the pole. The internal contactsurface has a definite cylindrical character in that its extent parallelto the axis and \relatively to its diameter, is materially greater thanthat of the known clamps referred to above. Such longie I ,7, no;tudinal extent relatively to the diameter is such; as: toprovide'a;contact area large enough to make the clamping pressureper unit of area'o'f'such low value as not to cause significant breaking of'thesurfacewood fibres. I

"The internal contact s'urfaces'are'provided with pointed pinswhicl'i'penetrate the surface of the pole to 'a substantial depth andthereby anchor th'e'a'ss'e'mbly' ofclamp elements againstitsgravitational tendency to slipdown the pole. The

pins penetrate the-timber by spreading the fibres' apart rather than by"severing the individual fibres. With" the object I of causing theleast' necessary disturbance to the fibre structure said-- pins are.directed parallel with the radial direction in which theparticular clampelement to which theyare attached, approaches the pole during thetightening movement of the clamp ele- The cl'ampfelements are themselvesprovided with tightening means and constitute the clamp. They are formedwith laterally extending ears through which clamping bolts are passed}and a cross arm is secured to one of the elements, as

by weldingyand the clamping'bcilts pass through the ears provided onthe-other,- or another; ne ment, and through holes in the cross arm.

Two forms of the invention are illustrated in the accompanying drawings,in which Figure I is a perspective View from beneath of an arrangementin which the cross arm is connected directly to one of the clampelements;

Figure II is a fragmentary perspective View showing an alternativearrangement of the penetrating pin formations.

In the drawings, the pole is numbered 2, and the clamp elements 3, 3',the clamp shown consisting of two elements which collectively constitutethe clamp assembly. Each of said elements 3 and 3' is provided with apair of pins 4 welded to it, the said pins passing through the elementand the pointed ends 5 penetrating the timber of the pole 2 when theassembly is tightened around the pole.

To enable the pins 4, 5 to penetrate the said timber by spreading thetimber fibres apart, rather than by severing them, the said pins are,preferably, arranged parallel with one another and with the radialdirection in which the clamp element 3 or 3 approaches the pole during.the tightening of the assembly around the pole.

Said clamp elements 3, 3' are formed with internal pole contactingsurfaces 3a which are of definite cylindrical character in that theextent e of the surface in a direction parallel with r the assembly axisis, relatively to the diameter with a considerable enough to make theclamping pressure per unit v of area of such low valueas;not-,t0.cause,sig-

nificant breaking of the surface fibres ofthe pole 2. l

The cross arm 6 is shown as welded-ton saddle I which'in turn is weldedto the-element}, The other of the elements 3' is formed withradl-allyextending lugs 8; and cross bolts 9 pass through said lugs and throughholes in the crossearm 6, the clamp assembly being tightened around thpolezthymeans cfithe nuts 10. g g :Ifit be required tmrctate the crossarm .Sabout the 1001s. :in :the arrangement of ,Figure ,I it isnecessary to :pry the elements out'of the =-pole .2

before said rotation can take place. Accordingly,

the 'arr..angement=of Figure :11 is provided-tore able rotation-to .bereadilyeifected, I

In Figure II the ;pins --4 are shown as screw-f threaded and theyare-screwed through thread ediholes providedin A the elements .3, .3 and:held in position against unintentional unscrewing .-.by lock-nuts?! 3.In attaching zthe clamp elements tothe pole,*,the pins I;are.initial1y'retracted, and

.A d vic for attachin parts :to wooden poles,-

ccmnrising clamp elements adapted collectively to encircle the pole .andmake internal contact is holes in the 4 V circumferential extent of thesubstantially cylindrical surface of the pole. the internal contactsurface of the clamp assembly having a definite cylindrical character inthat its extent parallel to the axis of the clamp assembly andrelatively to the diameter of the assembly is materially greater thanthat of the clamps at present in common use; pointed pins at theinternal contacting surface adapted to penetrate the surface of the poleto a substantial depth; a cross arm rigidly attached to one element ofthe clamp assembly and having a hole at each side of the element,lateral ears on the opposite element of the assembly; and clamping boltspassed. through the ears and through the cross arm. MAG NUS WILLIAMMANSON.

REFERENCES CITED The following references are of record in the flle ofthis patent: i a

, UNITED STATES PATENTS Number Name Date 734,620 Sears July 28, 1903743,964 Weir Nov. 10,1903

768,819 Palmer Aug. 30,1904 772,175 Palmer 0ct. 11, 1904 868,843 Clay-0ct. 22, 1907 878,867 Coldwell Feb. 11, 1908 964,140 Zahniser etal.July 12, 1910- .1,204,196 Schulz Nov. 7, 1916 1,485,629 Seeger Mar.4,1924 1,575,614 Blaw Mar. 9, 1926 1,588,810 Rudolph et al June 15, 19261,843,454 Manson Feb. 2, 1932 1,967,288 Cathcart July 24, 1934 2,060,171Burton Nov. 10, 1936- 2,118,467 Jones May 24, 1938 2,201,608 Causey May21, 1940 FOREIGN PATENTS 7 Number Country Date 425,376 Germany Feb. 18,1926 705,395 France June .5, 1931

